Boundary Layer Ingestion (“BLI”) typically involves placing the intake of a propulsion system close to the surface of the fuselage, which is usually accomplished by mounting the propulsion system to the aft section of an aircraft fuselage where the lower velocity of the boundary layer airflow can be ingested by the aft propulsion intake. The lower momentum boundary layer flow can then be used to increase engine performance. Conceptual designs and models for BLI exist, such as, for example, NASA's STARC-ABL (Single-aisle Turbo-electric Aircraft with an Aft Boundary Layer propulsor) concept, however, to date there has not been a detailed design of the external and internal structural integration of the aft fuselage and the aft propulsor. Thus, ambiguities exist with the design, shaping, mounting, and integration into the aircraft structure for elements of a BLI system such as the aft engine, aft fuselage, aft fuselage skin, aft longerons, and the like.
In addition, existing BLI models and conceptual designs by, among other things, their conceptual nature, lack the detail necessary to accurately determine the weight, cost, and desired manufacturing techniques for such an aircraft. Other drawbacks of existing systems also exist.